U.S. patent number 10,281,580 [Application Number 15/342,387] was granted by the patent office on 2019-05-07 for surveying system.
This patent grant is currently assigned to TOPCON Corporation. The grantee listed for this patent is TOPCON Corporation. Invention is credited to Tetsuji Anai, Kaoru Kumagai, Fumio Ohtomo, Hitoshi Otani.
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United States Patent |
10,281,580 |
Ohtomo , et al. |
May 7, 2019 |
Surveying system
Abstract
The invention provides a surveying system, which comprises a
surveying instrument, wherein the surveying instrument comprises a
measuring unit for performing a distance measurement by projecting
a distance measuring light toward an object to be measured and by
receiving a reflected distance measuring light from the object to
be measured, an image pickup unit having an image pickup optical
axis running in parallel to a projection optical axis of the
distance measuring light and for picking up an image including the
object to be measured, an attitude detecting unit provided
integrally with the measuring unit and for detecting a tilt angle
with respect to the horizontal of the measuring unit, a coordinates
acquiring unit for detecting a position of the surveying instrument
and an arithmetic processing unit, wherein a first image of the
object to be measured is acquired by the image pickup unit from a
first position where coordinates of the first position are acquired
by the coordinates acquiring unit, a second image of the object to
be measured is acquired by the image pickup unit from a second
position where coordinates of the second position are acquired by
the coordinates acquiring unit, wherein the measuring unit directs
a distance measuring optical axis toward common measuring points as
specified in the first image and the second image respectively,
projects the distance measuring light, and carries out a first
distance measurement from the first position and a second distance
measurement from the second position, and wherein the arithmetic
processing unit calculates horizontal distances from the first
position and the second position respectively based on the tilt
angles detected by the attitude detecting unit at the first
position and the second position, on the first distance measurement
and on the second distance measurement, and further the arithmetic
processing unit is configured to calculate a base line length based
on coordinates of the first position and on coordinates of the
second position and to carry out a trilateration with respect to
the measuring point based on the horizontal distance and on the
base line length.
Inventors: |
Ohtomo; Fumio (Saitama,
JP), Kumagai; Kaoru (Tokyo-to, JP), Otani;
Hitoshi (Tokyo-to, JP), Anai; Tetsuji (Tokyo-to,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
TOPCON Corporation |
Tokyo-to |
N/A |
JP |
|
|
Assignee: |
TOPCON Corporation (Tokyo-to,
JP)
|
Family
ID: |
58663685 |
Appl.
No.: |
15/342,387 |
Filed: |
November 3, 2016 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20170131404 A1 |
May 11, 2017 |
|
Foreign Application Priority Data
|
|
|
|
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Nov 10, 2015 [JP] |
|
|
2015-220474 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01S
17/48 (20130101); G01S 17/89 (20130101); G01S
7/4812 (20130101); G01C 15/002 (20130101); G01S
7/4814 (20130101); G01S 7/4817 (20130101) |
Current International
Class: |
G01C
3/08 (20060101); G01C 15/00 (20060101); G01S
17/89 (20060101); G01S 7/481 (20060101); G01S
17/48 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
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|
2006-170688 |
|
Jun 2006 |
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JP |
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2007-248156 |
|
Sep 2007 |
|
JP |
|
2009-210388 |
|
Sep 2009 |
|
JP |
|
Primary Examiner: Abraham; Samantha K
Attorney, Agent or Firm: Nields, Lemack & Frame, LLC
Claims
The invention claimed is:
1. A surveying system comprising: a surveying instrument, wherein
said surveying instrument comprises a measuring unit for performing
a distance measurement by projecting a distance measuring light
toward an object to be measured and by receiving a reflected
distance measuring light from said object to be measured, an image
pickup unit having an image pickup optical axis running in parallel
to a projection optical axis of said distance measuring light and
for picking up an image including said object to be measured, an
attitude detecting unit provided integrally with said measuring
unit and for detecting a tilt angle with respect to the horizontal
of said measuring unit, a coordinates acquiring unit for detecting
a position of said surveying instrument and an arithmetic
processing unit, wherein a first image of said object to be
measured is acquired by said image pickup unit from a first
position where coordinates of said first position are acquired by
said coordinates acquiring unit, a second image of said object to
be measured is acquired by said image pickup unit from a second
position where coordinates of said second position are acquired by
said coordinates acquiring unit, wherein said measuring unit
directs a distance measuring optical axis toward common measuring
points as specified in said first image and said second image
respectively, projects said distance measuring light, and carries
out a first distance measurement from said first position and a
second distance measurement from said second position, and wherein
said arithmetic processing unit calculates horizontal distances
from said first position and said second position respectively
based on the tilt angles detected by said attitude detecting unit
at said first position and said second position, on said first
distance measurement and on said second distance measurement, and
further said arithmetic processing unit is configured to calculate
a base line length based on the coordinates of said first position
and on the coordinates of said second position and to carry out a
trilateration with respect to said measuring point based on said
horizontal distance and on said base line length.
2. The surveying system according to claim 1, wherein said
coordinates acquiring unit is a GNSS device.
3. The surveying system according to claim 1, wherein said
surveying instrument is provided on an upper end of a monopod
having a known length, and said coordinates acquiring unit is
composed of said monopod and said attitude detecting unit for
detecting a tilt angle of said monopod.
4. The surveying system according to claim 3, wherein said
measuring instrument is provided at a known first installation
reference point via said monopod and is provided at a known second
installation reference point, said first position is obtained based
on a tilt angle detected by said attitude detecting unit at said
first installation reference point and on a length of said monopod,
said second position is obtained based on a tilt angle detected by
said attitude detecting unit at said second installation reference
point and on the length of said monopod, and said base line length
is obtained according to said first position and said second
position.
5. The surveying system according to claim 3, wherein said first
position is obtained by tilting said monopod in one direction, said
second position is obtained by tilting said monopod in the other
direction, further, coordinates of said first position are acquired
based on a tilt angle detected by said attitude detecting unit at
said first position and on the length of said monopod, coordinates
of said second position are acquired based on a tilt angle detected
by said attitude detecting unit at said second position and on the
length of said monopod, and said base line length is obtained
according to the coordinates of said first position and the
coordinates of said second position.
6. The surveying system according to claim 3, wherein said
surveying instrument is provided at an installation reference point
via said monopod and is provided at an installation point separated
by a distance as required, the coordinates of said first position
are acquired based on a tilt angle detected by said attitude
detecting unit at said installation reference point and on the
length of said monopod, the coordinates of said second position are
acquired based on a tilt angle detected by said attitude detecting
unit at said installation point, on a slope distance from said
second position to said installation reference point determined by
said surveying instrument, and on the length of said monopod, and
said base line length is obtained according to the coordinates of
said first position and the coordinates of said second
position.
7. The surveying system according to claim 3, wherein said
surveying instrument comprises a GNSS device, said surveying
instrument is provided at the installation reference point via said
monopod and is provided at the installation point separated by the
distance as required, the coordinates of said first position and
the coordinates of said second position are acquired by said GNSS
device respectively, and said base line length is obtained
according to the coordinates of said first position and the
coordinates of said second position.
8. The surveying system according to claim 1, wherein said
measuring point is specified in the second image by an image
matching of said first image and said second image.
9. The surveying system according to claim 1, further comprising an
optical axis deflecting unit as provided on said projection optical
axis of said distance measuring light, for deflecting said
projection optical axis as said distance measuring optical axis,
and capable of changing a deflection angle, wherein said arithmetic
processing unit controls said attitude detecting unit so that said
distance measuring light is irradiated to said measuring
points.
10. The surveying system according to claim 9, wherein said
arithmetic processing unit calculates a tilt angle of said distance
measuring optical axis with respect to the horizontal based on a
tilt angle detected by said attitude detecting unit and on a
deflection angle of said distance measuring optical axis detected
by said optical axis deflecting unit.
11. The surveying system according to claim 10, wherein said
attitude detecting unit comprises a tilt detecting unit as
rotatably supported around two axes perpendicular each other to an
outer frame and for detecting a tilting from the horizontal,
encoders provided on each of said axes, motors provided so as to
rotate each axis, and an arithmetic unit for driving/controlling
said motor based on a detection result from said tilt detecting
unit, wherein said arithmetic unit drives said motors so that said
tilt detecting unit detects the horizontal based on a signal from
said tilt detecting unit when said outer frame is tilted and
outputs a tilt angle based on outputs of said encoders when said
tilt detecting unit detects the horizontal.
12. The surveying system according to claim 11, wherein said tilt
detecting unit comprises a first tilt sensor for detecting the
horizontal with high accuracy and a second tilt sensor for
detecting the tilting with higher responsiveness than said first
tilt sensor, wherein said second tilt sensor detects the tilting
from the horizontal as detected by said first tilt sensor, and said
arithmetic unit is configured to detect a tilt angle based on a
detection signal from said second tilt sensor.
13. The surveying system according to claim 10, wherein said
optical axis deflecting unit is composed of a pair of optical
prisms in disk-like shape overlapped on each other, said first
optical axis deflecting unit is composed of first prism elements
provided at a center of said optical prisms, a second optical axis
deflecting unit is composed of second prism elements provided
around said first prism elements, each optical prism can be
independently rotated respectively, and a rotation angle of each
optical prism can be individually detected.
14. The surveying system according to claim 9 further comprising a
first optical axis deflecting unit disposed on said projection
optical axis of said distance measuring light for deflecting said
distance measuring optical axis at a deflection angle as required
and in a direction as required, a second optical axis deflecting
unit disposed on a light receiving optical axis for deflecting said
reflected distance measuring light at the same deflection angle and
in the same direction as said first optical axis deflecting unit
and a projecting direction detecting unit for detecting a
deflection angle and a deflecting direction by said first optical
axis deflecting unit, wherein it is so arranged that said distance
measuring light is projected through said first optical axis
deflecting unit and said reflected distance measuring light is
received by a photodetector through said second optical axis
deflecting unit, three-dimensional data of said measuring point is
acquired based on a distance measuring result of said distance
measuring unit and on a detection result of said projecting
direction detecting unit, and said three-dimensional data is
corrected based on the result detected by said attitude detecting
unit.
15. The surveying system according to claim 14, wherein said
optical axis deflecting unit is composed of a pair of optical
prisms in disk-like shape overlapped on each other, said first
optical axis deflecting unit is composed of first prism elements
provided at a center of said optical prisms, a second optical axis
deflecting unit is composed of second prism elements provided
around said first prism elements, each optical prism can be
independently rotated respectively, and a rotation angle of each
optical prism can be individually detected.
16. The surveying system according to claim 9, wherein said optical
axis deflecting unit is composed of a pair of optical prisms in
disk-like shape overlapped on each other, said first optical axis
deflecting unit is composed of first prism elements provided at a
center of said optical prisms, a second optical axis deflecting
unit is composed of second prism elements provided around said
first prism elements, each optical prism can be independently
rotated respectively, and a rotation angle of each optical prism
can be individually detected.
17. The surveying system according to claim 9, wherein said
attitude detecting unit comprises a tilt detecting unit as
rotatably supported around two axes perpendicular each other to an
outer frame and for detecting a tilting from the horizontal,
encoders provided on each of said axes, motors provided so as to
rotate each axis, and an arithmetic unit for driving/controlling
said motor based on a detection result from said tilt detecting
unit, wherein said arithmetic unit drives said motors so that said
tilt detecting unit detects the horizontal based on a signal from
said tilt detecting unit when said outer frame is tilted and
outputs a tilt angle based on outputs of said encoders when said
tilt detecting unit detects the horizontal.
18. The surveying system according to claim 17, wherein said tilt
detecting unit comprises a first tilt sensor for detecting the
horizontal with high accuracy and a second tilt sensor for
detecting the tilting with higher responsiveness than said first
tilt sensor, wherein said second tilt sensor detects the tilting
from the horizontal as detected by said first tilt sensor, and said
arithmetic unit is configured to detect a tilt angle based on a
detection signal from said second tilt sensor.
19. The surveying system according to claim 1, wherein said
attitude detecting unit comprises a tilt detecting unit as
rotatably supported around two axes perpendicular each other to an
outer frame and for detecting a tilting from the horizontal,
encoders provided on each of said axes, motors provided so as to
rotate each axis, and an arithmetic unit for driving/controlling
said motor based on a detection result from said tilt detecting
unit, wherein said arithmetic unit drives said motors so that said
tilt detecting unit detects the horizontal based on a signal from
said tilt detecting unit when said outer frame is tilted and
outputs a tilt angle based on outputs of said encoders when said
tilt detecting unit detects the horizontal.
20. The surveying system according to claim 19, wherein said tilt
detecting unit comprises a first tilt sensor for detecting the
horizontal with high accuracy and a second tilt sensor for
detecting the tilting with higher responsiveness than said first
tilt sensor, wherein said second tilt sensor detects the tilting
from the horizontal as detected by said first tilt sensor, and said
arithmetic unit is configured to detect a tilt angle based on a
detection signal from said second tilt sensor.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a surveying system for performing
a trilateration in a simple and easy manner.
In general, a surveying expresses a plurality of measuring points,
which are objects on a ground surface, in relation to a horizontal
distance and a height. As a surveying instrument to be used for the
surveying, a total station is known, for instance.
On a plurality of the measuring points, a distance (a slope
distance), a vertical angle, and a horizontal angle are measured by
the total station respectively, and the relations between the
measuring points are obtained respectively.
Since in the total station, it is necessary to measure an angle
with high accuracy, the total station must be installed via a
tripod at an installation point (a reference point), and further
must be leveled horizontally with high accuracy. For this reason, a
time for installing is required, and further, a high skill is
required.
Further, since in the total station, it is necessary to sight a
plurality of the measuring points each time, much time is required
for sighting, and a burden on the operator is heavy.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a surveying
system, by which it is possible to omit an angle measurement, which
a burden of an operation is heavy, and to perform a trilateration
easily.
To attain the object as described above, a surveying system
according to the present invention comprises a surveying
instrument, wherein the surveying instrument comprises a measuring
unit for performing a distance measurement by projecting a distance
measuring light toward an object to be measured and by receiving a
reflected distance measuring light from the object to be measured,
an image pickup unit having an image pickup optical axis running in
parallel to a projection optical axis of the distance measuring
light and for picking up an image including the object to be
measured, an attitude detecting unit provided integrally with the
measuring unit and for detecting a tilt angle with respect to the
horizontal of the measuring unit, a coordinates acquiring unit for
detecting a position of the surveying instrument and an arithmetic
processing unit, wherein a first image of the object to be measured
is acquired by the image pickup unit from a first position where
coordinates of the first position are acquired by the coordinates
acquiring unit, a second image of the object to be measured is
acquired by the image pickup unit from a second position where
coordinates of the second position are acquired by the coordinates
acquiring unit, wherein the measuring unit directs a distance
measuring optical axis toward common measuring points as specified
in the first image and the second image respectively, projects the
distance measuring light, and carries out a first distance
measurement from the first position and a second distance
measurement from the second position, and wherein the arithmetic
processing unit calculates horizontal distances from the first
position and the second position respectively based on the tilt
angles detected by the attitude detecting unit at the first
position and the second position, on the first distance measurement
and on the second distance measurement, and further the arithmetic
processing unit is configured to calculate a base line length based
on the coordinates of the first position and on the coordinates of
the second position and to carry out a trilateration with respect
to the measuring point based on the horizontal distance and on the
base line length.
Further, in the surveying system according to the present
invention, the coordinates acquiring unit is a GNSS device.
Further, in the surveying system according to the present
invention, the surveying instrument is provided on an upper end of
a monopod having a known length, and the coordinates acquiring unit
is composed of the monopod and the attitude detecting unit for
detecting a tilt angle of the monopod.
Further, in the surveying system according to the present
invention, the measuring point is specified in the second image by
an image matching of the first image and the second image.
Further, in the surveying system according to the present
invention, the measuring instrument is provided at a known first
installation reference point via the monopod and is provided at a
known second installation reference point, the first position is
obtained based on a tilt angle detected by the attitude detecting
unit at the first installation reference point and on a length of
the monopod, the second position is obtained based on a tilt angle
detected by the attitude detecting unit at the second installation
reference point and on the length of the monopod, and the base line
length is obtained according to the first position and the second
position.
Further, in the surveying system according to the present
invention, the first position is obtained by tilting the monopod in
one direction, the second position is obtained by tilting the
monopod in the other direction, further, coordinates of the first
position are acquired based on a tilt angle detected by the
attitude detecting unit at the first position and on the length of
the monopod, coordinates of the second position are acquired based
on a tilt angle detected by the attitude detecting unit at the
second position and on the length of the monopod, and the base line
length is obtained according to the coordinates of the first
position and the coordinates of the second position.
Further, in the surveying system according to the present
invention, the surveying instrument is provided at an installation
reference point via the monopod and is provided at an installation
point separated by a distance as required, the coordinates of the
first position are acquired based on a tilt angle detected by the
attitude detecting unit at the installation reference point and on
the length of the monopod, the coordinates of the second position
are acquired based on a tilt angle detected by the attitude
detecting unit at the installation point, on a slope distance from
the second position to the installation reference point determined
by the surveying instrument, and on the length of the monopod, and
the base line length is obtained according to the coordinates of
the first position and the coordinates of the second position.
Further, in the surveying system according to the present
invention, the surveying instrument comprises a GNSS device, the
surveying instrument is provided at the installation reference
point via the monopod and is provided at the installation point
separated by the distance as required, the coordinates of the first
position and the coordinates of the second position are acquired by
the GNSS device respectively, and the base line length is obtained
according to the coordinates of the first position and the
coordinates of the second position.
Further, the surveying system according to the present invention
further comprises an optical axis deflecting unit as provided on
the projection optical axis of the distance measuring light, for
deflecting the projection optical axis as the distance measuring
optical axis, and capable of changing a deflection angle, wherein
the arithmetic processing unit controls the attitude detecting unit
so that the distance measuring light is irradiated to the measuring
points.
Further, in the surveying system according to the present
invention, the arithmetic processing unit calculates a tilt angle
of the distance measuring optical axis with respect to the
horizontal based on a tilt angle detected by the attitude detecting
unit and on a deflection angle of the distance measuring optical
axis detected by the optical axis deflecting unit.
Further, in the surveying system according to the present
invention, the attitude detecting unit comprises a tilt detecting
unit as rotatably supported around two axes perpendicular each
other to an outer frame and for detecting a tilting from the
horizontal, encoders provided on each of the axes, motors provided
so as to rotate each axis, and an arithmetic unit for
driving/controlling the motor based on a detection result from the
tilt detecting unit, wherein the arithmetic unit drives the motors
so that the tilt detecting unit detects the horizontal based on a
signal from the tilt detecting unit when the outer frame is tilted
and outputs a tilt angle based on outputs of the encoders when the
tilt detecting unit detects the horizontal.
Further, in the surveying system according to the present
invention, the tilt detecting unit comprises a first tilt sensor
for detecting the horizontal with high accuracy and a second tilt
sensor for detecting the tilting with higher responsiveness than
the first tilt sensor, wherein the second tilt sensor detects the
tilting from the horizontal as detected by the first tilt sensor,
and the arithmetic unit is configured to detect a tilt angle based
on a detection signal from the second tilt sensor.
Further, the surveying system according to the present invention
further comprises a first optical axis deflecting unit disposed on
the projection optical axis of the distance measuring light for
deflecting the distance measuring optical axis at a deflection
angle as required and in a direction as required, a second optical
axis deflecting unit disposed on a light receiving optical axis for
deflecting the reflected distance measuring light at the same
deflection angle and in the same direction as the first optical
axis deflecting unit and a projecting direction detecting unit for
detecting a deflection angle and a deflecting direction by the
first optical axis deflecting unit, wherein it is so arranged that
the distance measuring light is projected through the first optical
axis deflecting unit and the reflected distance measuring light is
received by a photodetector through the second optical axis
deflecting unit, three-dimensional data of the measuring point is
acquired based on a distance measuring result of the distance
measuring unit and on a detection result of the projecting
direction detecting unit, and the three-dimensional data is
corrected based on the result detected by the attitude detecting
unit.
Furthermore, in the surveying system according to the present
invention, the optical axis deflecting unit is composed of a pair
of optical prisms in disk-like shape overlapped on each other, the
first optical axis deflecting unit is composed of first prism
elements provided at a center of the optical prisms, a second
optical axis deflecting unit is composed of second prism elements
provided around the first prism elements, each optical prism can be
independently rotated respectively, and a rotation angle of each
optical prism can be individually detected.
According to the present invention, the surveying system comprises
a surveying instrument, wherein the surveying instrument comprises
a measuring unit for performing a distance measurement by
projecting a distance measuring light toward an object to be
measured and by receiving a reflected distance measuring light from
the object to be measured, an image pickup unit having an image
pickup optical axis running in parallel to a projection optical
axis of the distance measuring light and for picking up an image
including the object to be measured, an attitude detecting unit
provided integrally with the measuring unit and for detecting a
tilt angle with respect to the horizontal of the measuring unit, a
coordinates acquiring unit for detecting a position of the
surveying instrument and an arithmetic processing unit, wherein a
first image of the object to be measured is acquired by the image
pickup unit from a first position where coordinates of the first
position are acquired by the coordinates acquiring unit, a second
image of the object to be measured is acquired by the image pickup
unit from a second position where coordinates of the second
position are acquired by the coordinates acquiring unit, wherein
the measuring unit directs a distance measuring optical axis toward
common measuring points as specified in the first image and the
second image respectively, projects the distance measuring light,
and carries out a first distance measurement from the first
position and a second distance measurement from the second
position, and wherein the arithmetic processing unit calculates
horizontal distances from the first position and the second
position respectively based on the tilt angles detected by the
attitude detecting unit at the first position and the second
position, on the first distance measurement and on the second
distance measurement, and further the arithmetic processing unit is
configured to calculate a base line length based on the coordinates
of the first position and on the coordinates of the second position
and to carry out a trilateration with respect to the measuring
point based on the horizontal distance and on the base line length.
As a result, the surveying of the measuring point can be performed
without performing a leveling operation of the surveying instrument
and without a measuring a vertical angle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematical perspective view of an embodiment of the
present invention.
FIG. 2 is a schematical block diagram of a surveying instrument
according to the present embodiment.
FIG. 3 is an arrow view along line A in FIG. 2.
FIG. 4 is a plan view of an attitude detecting unit to be used in
the present embodiment.
FIG. 5 is a schematical block diagram of the attitude detecting
unit.
FIG. 6A, FIG. 6B and FIG. 6C are explanatory drawings to show an
operation of an optical axis deflecting unit.
FIG. 7A and FIG. 7B are explanatory drawings to show a relation
between an acquired image and a scanning locus.
FIG. 8 is an explanatory drawing to show a relation between an
object to be measured and a vertical line.
FIG. 9A, FIG. 9B and FIG. 9C are explanatory drawings to show a
relation between a picked up image and a vertical image.
FIG. 10 is an explanatory drawing of a first embodiment in a
trilateration.
FIG. 11 is an explanatory drawing of a second embodiment in the
trilateration.
FIG. 12 is an explanatory drawing about a relative orientation
operation in an image matching.
FIG. 13 is a drawing to show an equation to obtain parameters in a
relative orientation.
FIG. 14 is an explanatory drawing of a third embodiment in the
trilateration.
FIG. 15 is an explanatory drawing of a fourth embodiment in the
trilateration.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A description will be given below on an embodiment of the present
invention by referring to the attached drawings.
First, referring to FIG. 1, a description will be given on an
outline of a surveying system according to the present
embodiment.
In FIG. 1, reference numeral 1 denotes a surveying instrument, and
reference numeral 2 denotes a monopod which has a known length. The
surveying instrument 1 is provided on an upper end of the monopod
2. A lower end of the monopod 2 is designed as a tip and is
installed on an installation reference point R, which is already
known. By the surveying instrument 1, a measurement can be
performed according to a prism measurement mode in which an object
to be measured is a prism, and in a case where the object to be
measured is a structure, or the like, the measurement can be
performed according to a non-prism measurement mode without using
the prism.
An axis 3 of the monopod 2 is set so as to pass through a
mechanical reference point O of the surveying instrument 1.
Further, in the figure, reference numeral 4 denotes a distance
measuring optical axis, and reference numeral 5 denotes an image
pickup optical axis. The distance measuring optical axis 4
perpendicularly crosses the axis 3, and the image pickup optical
axis 5 runs in parallel to the distance measuring optical axis 4.
Further, a straight line running perpendicularly to a plane
including the axis 3 and the distance measuring optical axis 4 and
passing through the mechanical reference point O is defined as a
horizontal reference line 6.
Therefore, in the present embodiment, the axis 3, the distance
measuring optical axis 4 and the horizontal reference line 6 are
arranged so as to orthogonalize each other at the mechanical
reference point O. Further, a distance between the distance
measuring optical axis 4 and the image pickup optical axis 5 is
already known, and a distance L between the lower end of the
monopod 2 and the mechanical reference point O is also already
known.
In a case where the surveying instrument 1 is installed at the
installation reference point R, the surveying instrument 1 tilts
(inclines) in two horizontal directions around the installation
reference point R as a center. In the present embodiment, an angle
to be tilted in a vertical direction with the distance measuring
optical axis 4 as a reference is defined as a flap angle .omega.,
and an angle to be tilted in the vertical direction with the
horizontal reference line 6 as the reference is defined as an
inclining angle .kappa..
Referring to FIG. 2 and FIG. 3, a description will be given on the
surveying instrument 1.
The surveying instrument 1 has a display unit 11 and an operation
unit 12 on a back surface of a casing 7. Further, the surveying
instrument 1 primarily comprises a measuring unit 20 having the
distance measuring optical axis 4, an arithmetic processing unit
24, a projecting direction detecting unit 25 for detecting a
projecting direction of a distance measuring light, an attitude
detecting unit 26 for detecting a tilting in the two horizontal
directions of the surveying instrument 1, an image pickup unit 27
having the image pickup optical axis 5, and an optical axis
deflecting unit 36 for deflecting the distance measuring optical
axis 4, or the like inside the casing 7. Therefore, the measuring
unit 20, the attitude detecting unit 26, the image pickup unit 27,
and the optical axis deflecting unit 36 are integrated together. It
is to be noted that the display unit 11 may be designed as a touch
panel and may be also served as the operation unit 12.
The measuring unit 20 comprises a distance measuring light
projecting unit 21, a light receiving unit 22, and a distance
measuring unit 23.
The distance measuring light projecting unit 21 projects the
distance measuring light. The distance measuring light projecting
unit 21 has a projection optical axis 31, a light emitting element
32, for instance, a laser diode (LD) is provided on the projection
optical axis 31. Further, a projecting lens 33 is provided on the
projection optical axis 31.
Further, a first reflection mirror 34 as a deflecting optical
component is provided on the projection optical axis 31. Further, a
second reflection mirror 35 as the deflecting optical component is
faced with the first reflection mirror 34 and disposed on a light
receiving optical axis 37 (to be described later).
By the first reflection mirror 34 and the second reflection mirror
35, the projection optical axis 31 is coincided with the distance
measuring optical axis 4. The optical axis deflecting unit 36 is
disposed on the distance measuring optical axis 4.
The light receiving unit 22 receives a reflected distance measuring
light from the object to be measured. The light receiving unit 22
has the light receiving optical axis 37 running in parallel to the
projection optical axis 31, and the light receiving optical axis 37
is commonly used as the distance measuring optical axis 4.
A photodetector 38, for instance, a photo diode (PD), is provided
on the light receiving optical axis 37. Further, an image forming
lens 39 is disposed on the light receiving optical axis 37. The
image forming lens 39 forms an image of the reflected distance
measuring light on the photodetector 38. The photodetector 38
receives the reflected distance measuring light and produces a
light receiving signal. The light receiving signal is inputted to
the distance measuring unit 23.
Further, on the light receiving optical axis 37, the optical axis
deflecting unit 36 is arranged on an objective side of the image
forming lens 39.
The distance measuring unit 23 controls the light emitting element
32 and emits a laser beam as the distance measuring light. By the
optical axis deflecting unit 36 (a distance measuring light
deflecting unit 36a (to be described later)), the distance
measuring optical axis 4 is deflected so as to direct toward a
measuring point.
The reflected distance measuring light as reflected from the object
to be measured enters the light receiving unit 22 via the optical
axis deflecting unit 36 (a reflected distance measuring light
deflecting unit 36b (to be described later)) and the image forming
lens 39. The reflected distance measuring light deflecting unit 36b
deflects again the distance measuring optical axis 4 as deflected
by the distance measuring light deflecting unit 36a so that the
distance measuring optical axis 4 is returned to an original
condition, and the reflected distance measuring light is received
by the photodetector 38.
The photodetector 38 sends the light receiving signal to the
distance measuring unit 23. The distance measuring unit 23 performs
a distance measurement of the measuring point (a point where the
distance measuring light is projected) based on the light receiving
signal from the photodetector 38.
The arithmetic processing unit 24 is configured by an input/output
control unit, an arithmetic unit (CPU), a storage unit, or the
like. The storage unit stores programs such as a distance measuring
program for controlling a distance measuring operation, a control
program for controlling drivings of motors 47a and 47b (to be
described later), an image program for performing an image
processing such as an image matching, or the like, an input/output
control program, a directional angle calculating program for
calculating directional angles (a horizontal angle and a vertical
angle) of the distance measuring optical axis 4 based on
calculation results in a projecting direction from the projecting
direction detecting unit 25, or the like. Further, in the storage
unit, measurement results such as distance measuring data, image
data, or the like, are stored.
A description will be given on the optical axis deflecting unit
36.
In the optical axis deflecting unit 36, a pair of optical prisms
41a and 41b is provided. Each of the optical prisms 41a and 41b is
designed in disk-like shape, disposed perpendicularly crossing the
light receiving optical axis 37, overlapped on each other, and
arranged in parallel to each other. As for the optical prisms 41a
and 41b, a Fresnel prism is preferably used respectively in order
to reduce a size of an instrument.
A central part of the optical axis deflecting unit 36 is designed
as the distance measuring light deflecting unit 36a where the
distance measuring light passes, and a part except the central part
is designed as the reflected distance measuring light deflecting
unit 36b.
The Fresnel prism used as the optical prisms 41a and 41b is
composed of prism elements 42a and 42b and a large number of prism
elements 43a and 43b arranged in parallel to each other
respectively and has a plate shape. The prism element 42a and the
prism element 42b as well as the prism element 43a and the prism
element 43b have the same optical characteristics respectively.
The prism elements 42a and 42b make up the distance measuring light
deflecting unit 36a, and the prism elements 43a and 43b make up the
reflected distance measuring light deflecting unit 36b.
The Fresnel prism may be manufactured by an optical glass but may
be molded by an optical plastic material. By molding the Fresnel
prism by the optical plastic material, a low cost Fresnel prism can
be manufactured.
Each of the optical prisms 41a and 41b is arranged in such a manner
that each of the optical prisms 41a and 41b rotates with the light
receiving optical axis 37 as the center individually. The optical
prisms 41a and 41b are controlled in such a manner that rotating
directions, rotation amounts and rotating speeds are independently
controlled. As a result, the optical prisms 41a and 41b deflect the
distance measuring optical axis 4 of the distance measuring light
as emitted in an arbitrary deflecting direction, and deflect the
light receiving optical axis 37 of the reflected distance measuring
light as received in parallel to the distance measuring optical
axis 4.
Outer shapes of the optical prisms 41a and 41b are arranged in
disk-like shape with the light receiving optical axis 37 as the
center, respectively. Taking an expansion of the reflected distance
measuring light into consideration, diameters of the optical prisms
41a and 41b are set so that a sufficient light amount can be
obtained.
A ring gear 44a is fitted with an outer periphery of the optical
prism 41a and a ring gear 44b is fitted with an outer periphery of
the optical prism 41b.
A driving gear 46a meshes with the ring gear 44a, and the driving
gear 46a is fixed to an output shaft of the motor 47a. A driving
gear 46b meshes with the ring gear 44b, and the driving gear 46b is
fixed to an output shaft of the motor 47b. The motors 47a and 47b
are electrically connected to the arithmetic processing unit
24.
As the motors 47a and 47b, motors capable of detecting a rotation
angle or motors which rotate corresponding to a driving input
value, for instance, a pulse motor is used. Alternatively, a
rotation amount of the motor may be detected by using a rotation
detector for detecting a rotation amount (rotation angle) of the
motor such as an encoder (not shown), for instance, or the like.
The rotation amounts of the motors 47a and 47b are detected
respectively by the projecting direction detecting unit 25, and the
motors 47a and 47b are individually controlled by the arithmetic
processing unit 24 based on detection results of the projecting
direction detecting unit 25.
The driving gears 46a and 46b and the motors 47a and 47b are
provided at positions not interfering with the distance measuring
light projecting unit 21, for instance, on a lower side of the ring
gears 44a and 44b.
The projecting lens 33, the distance measuring light deflecting
unit 36a, or the like, make up a projecting optical system. The
reflected distance measuring light deflecting unit 36b and the
image forming lens 39, or the like, make up a light receiving
optical system.
The projecting direction detecting unit 25 counts driving pulses
input to the motors 47a and 47b and detects the rotation angles of
the motors 47a and 47b. Alternatively, the projecting direction
detecting unit 25 detects the rotation angles of the motors 47a and
47b based on signals from the encoders.
Further, the projecting direction detecting unit 25 calculates
rotation positions of the optical prisms 41a and 41b based on the
rotation angles of the motors 47a and 47b, and calculates a
deflection angle (a deflecting direction) and the projecting
direction of the distance measuring light based on refractive
indexes and the rotation positions of the distance measuring light
deflecting unit 36a (that is, the prism elements 42a and 42b). A
calculation result is inputted to the arithmetic processing unit
24.
In the surveying instrument 1, the attitude detecting unit 26
detects an attitude (a tilt angle and a tilting direction) of the
distance measuring unit 23 with respect to the projection optical
axis 31. A detection result is inputted to the arithmetic
processing unit 24.
A description will be given below on the attitude detecting unit 26
by referring to FIG. 4 and FIG. 5. It is to be noted that FIG. 4
shows a plan view, and in the description as given below, the top
and bottom corresponds to the top and bottom in FIG. 4, and the
left and right corresponds to the left and right in FIG. 4.
Inside an outer frame 51 with a rectangular frame shape, an inner
frame 53 with a rectangular frame shape is provided, and inside the
inner frame 53, a tilt detecting unit 56 is provided.
From an upper surface and a lower surface of the inner frame 53,
longitudinal shafts 54 and 54 are protruded. The longitudinal
shafts 54 and 54 are rotatably fitted with bearings 52 and 52 as
provided on the outer frame 51. The longitudinal shafts 54 and 54
have a longitudinal axis 14, and the inner frame 53 is capable of
rotating freely by 360.degree. in a left-to-right direction around
the longitudinal shafts 54 and 54 as the center. The longitudinal
axis 14 of the longitudinal shafts 54 and 54 is arranged so as to
coincide with either one of the distance measuring optical axis 4
or the horizontal reference line 6, for instance, with the distance
measuring optical axis 4, or to run in parallel to each other.
The tilt detecting unit 56 is supported by a lateral shaft 55, and
both end portions of the lateral shaft 55 are rotatably fitted with
bearings 57 and 57 provided on the inner frame 53. The lateral
shaft 55 has a lateral axis 15 perpendicular to the longitudinal
axis 14, and the tilt detecting unit 56 is capable of rotating
freely by 360.degree. in an up-to-bottom direction around the
lateral shaft 55 as the center. The lateral axis 15 of the lateral
shaft 55 is arranged so as to coincide with either different one of
the distance measuring optical axis 4 or the horizontal reference
line 6, for instance, with the horizontal reference line 6, or to
run in parallel to each other.
That is, the tilt detecting unit 56 is configured so as to be
supported via a zimbal mechanism, which is capable of rotating
freely by 360.degree. in two axial directions with respect to the
outer frame 51.
On one of the longitudinal shafts 54 and 54, for instance, a first
gear 58 is attached to the lower longitudinal shaft 54, and a first
driving gear 59 meshes with the first gear 58. Further, a first
motor 61 is provided on a lower surface of the outer frame 51, and
the first driving gear 59 is attached to an output shaft of the
first motor 61.
On the other of the longitudinal shafts 54 and 54, a first encoder
62 is attached. The first encoder 62 is configured so as to detect
a rotation angle in the left-to-right direction of the inner frame
53 with respect to the outer frame 51. That is, referring to FIG.
1, the first encoder 62 detects the flap angle .omega..
On one end of the lateral shaft 55, a second gear 63 is attached,
and a second driving gear 64 meshes with the second gear 63.
Further, on a side surface (left side surface in the figure) of the
inner frame 53, a second motor 65 is attached, and the second
driving gear 64 is attached to an output shaft of the second motor
65.
On the other end of the lateral shaft 55, a second encoder 66 is
attached. The second encoder 66 is configured so as to detect a
rotation angle in the up-to-bottom direction of the tilt detecting
unit 56 with respect to the inner frame 53. That is, referring to
FIG. 1, the second encoder 66 detects the inclining angle
.kappa..
The first encoder 62 and the second encoder 66 are electrically
connected to an arithmetic unit 68, and a detection result is
inputted to the arithmetic unit 68.
The tilt detecting unit 56 has a first tilt sensor 71 and a second
tilt sensor 72, and the first tilt sensor 71 and the second tilt
sensor 72 are electrically connected to the arithmetic unit 68. The
detection results by the first tilt sensor 71 and the second tilt
sensor 72 are inputted to the arithmetic unit 68.
Further description will be given on the attitude detecting unit 26
by referring to FIG. 5.
The attitude detecting unit 26 comprises the first encoder 62, the
second encoder 66, the first tilt sensor 71, the second tilt sensor
72, the arithmetic unit 68, the first motor 61, and the second
motor 65. Further, the attitude detecting unit 26 comprises a
storage unit 73 and an input/output control unit 74.
In the storage unit 73, programs such as a calculation program for
an attitude detection and the like, and data such as calculation
data and the like are stored.
The input/output control unit 74 drives the first motor 61 and the
second motor 65 based on a control instruction output from the
arithmetic unit 68 and outputs a result of a tilt detection
calculated by the arithmetic unit 68 as a detection signal.
The first tilt sensor 71 is for detecting the horizontal with high
accuracy, for instance, a tilt detector in which a detection light
incidents to a horizontal liquid surface and the horizontal is
detected according to a change of a reflection angle of a reflected
light, or a bubble tube which detects a tilting according to a
positional change of an air bubble sealed in a tube. Further, the
second tilt sensor 72 is for detecting a tilt change with high
responsiveness, for instance, an acceleration sensor.
It is to be noted that both the first tilt sensor 71 and the second
tilt sensor 72 can individually detect tiltings in the two axial
directions, which are a rotating direction (a tilting direction)
detected by the first encoder 62 and a rotating direction (a
tilting direction) detected by the second encoder 66.
The arithmetic unit 68 calculates a tilt angle and a tilting
direction based on detection results from the first tilt sensor 71
and the second tilt sensor 72. Further, the arithmetic unit 68
calculates a tilt angle of the surveying instrument 1 with respect
to a verticality based on a rotation angle of the first encoder 62
and on a rotation angle of the second encoder 66, which correspond
to the tilt angle and the tilting direction.
By synthesizing the rotation angle of the first encoder 62 and the
rotation angle of the second encoder 66 as calculated, the tilt
angle and the tilting direction are calculated. The tilt angle and
the tilting direction correspond to a tilt angle and a tilting
direction (a relative tilt angle) of the casing 7 with respect to
the horizontal, i.e. a tilt angle and a tilting direction (a
relative tilt angle) of the measuring unit 20.
Thus, the first motor 61, the second motor 65, the first encoder
62, the second encoder 66, and the arithmetic unit 68 make up a
relative tilt angle detecting unit.
It is to be noted that in a case where the outer frame 51 is
installed horizontally, the attitude detecting unit 26 is set such
that the first tilt sensor 71 detects the horizontal, and further,
is set such that an output of the first encoder 62 and an output of
the second encoder 66 both indicate a reference position (rotation
angle at 0').
A description will be given on an operation of the attitude
detecting unit 26.
First, a description will be given below on a case where a tilting
is detected with high accuracy.
When the attitude detecting unit 26 is tilted, the first tilt
sensor 71 outputs a signal corresponding to a tilting.
The arithmetic unit 68 calculates a tilt angle and a tilting
direction based on the signal from the first tilt sensor 71 and
further calculates rotation amounts of the first motor 61 and the
second motor 65 in order to make the tilt angle and the tilting
direction 0 based on a calculation result. The arithmetic unit 68
outputs a driving command for driving the first motor 61 and the
second motor 65 by the rotation amounts via the input/output
control unit 74.
According to the driving command from the arithmetic unit 68, the
first motor 61 and the second motor 65 are driven so as to be
tilted oppositely to the calculated tilt angle and the tilting
direction. Rotation amounts (the rotation angles) of the motors are
detected by the first encoder 62 and the second encoder 66
respectively, and when the rotation angles reach the calculation
results, the drivings of the first motor 61 and the second motor 65
are stopped.
In this state, under the condition where the outer frame 51 and the
inner frame 53 are tilted, the tilt detecting unit 56 is controlled
to the horizontal.
Therefore, in order to make the tilt detecting unit 56 horizontal,
the tilt angles, at which the inner frame 53 and the tilt detecting
unit 56 are tilted by the first motor 61 and the second motor 65,
are acquired based on the rotation angles as detected by the first
encoder 62 and the second encoder 66.
The arithmetic unit 68 calculates the tilt angle and the tilting
direction of the attitude detecting unit 26 with respect to the
horizontal based on the detection results of the first encoder 62
and the second encoder 66 when the first tilt sensor 71 detects the
horizontal. The calculation result indicates the attitude of the
attitude detecting unit 26 after the attitude detecting unit 26 is
tilted.
Further, the rotation angle as detected by the first encoder 62
corresponds to the flap angle .omega., and the rotation angle as
detected by the second encoder 66 corresponds to the inclining
angle .kappa..
Therefore, the tilt angle and the tilting direction as calculated
by the arithmetic unit 68 are a tilt angle and a tilting direction
of the surveying instrument 1 with respect to the horizontal.
The arithmetic unit 68 outputs the calculated tilt angle and the
tilting direction to an outside via the input/output control unit
74 as a detection signal of the attitude detecting unit 26.
In the attitude detecting unit 26, as a structure shown in FIG. 4,
there is nothing which restricts rotations of the tilt detecting
unit 56 and the inner frame 53. Therefore, the tilt detecting unit
56 and the inner frame 53 can both rotate by 360.degree. or more.
That is, no matter what attitude the attitude detecting unit 26
takes (even in a case where the attitude detecting unit 26 is
upside down, for instance), the attitude detection in all
directions can be performed.
In a case where high responsiveness is required, although the
attitude detection and an attitude control are performed based on
the detection result of the second tilt sensor 72, the second tilt
sensor 72 has poorer detection accuracy than the first tilt sensor
71 in general.
In the present embodiment, by comprising the first tilt sensor 71
with high accuracy and the second tilt sensor 72 with high
responsiveness, the attitude control is performed based on the
detection results of the second tilt sensor 72, and the attitude
detection with high accuracy can be performed by the first tilt
sensor 71.
That is, based on the tilt angle as detected by the second tilt
sensor 72, the first motor 61 and the second motor 65 are driven so
that the tilt angle becomes 0.degree.. Further, by continuing the
driving of the first motor 61 and the second motor 65 until the
first tilt sensor 71 detects the horizontal, the attitude can be
detected with high accuracy. If a deviation occurs between values
of the first encoder 62 and the second encoder 66 when the first
tilt sensor 71 detects the horizontal (that is, an actual tilt
angle) and the tilt angle as detected by the second tilt sensor 72,
the tilt angle of the second tilt sensor 72 can be calibrated based
on the deviation.
Therefore, by obtaining a relation between the detected tilt angle
of the second tilt sensor 72 and the tilt angle which is obtained
based on the horizontal detection by the first tilt sensor 71 and
the detection result of the first encoder 62 and the second encoder
66 in advance, the tilt angle detected by the second tilt sensor 72
can be calibrated. Thereby, accuracy of the attitude detection with
high responsiveness by the second tilt sensor 72 can be
improved.
Next, the image pickup unit 27 has the image pickup optical axis 5.
Under the condition where the optical axis deflecting unit 36 does
not deflect the distance measuring optical axis 4, the image pickup
optical axis 5 is set so as to run in parallel to the distance
measuring optical axis 4. On the image pickup optical axis 5, an
image forming lens 48 and an image pickup element 49 are
provided.
A field angle of the image pickup unit 27 is set so as to be
equivalent to or somewhat larger than an area where an optical axis
can be deflected by the optical axis deflecting unit 36. The field
angle of the image pickup unit 27 is set to 5.degree., for
instance.
Further, image pickup element 49 is a CCD or a CMOS sensor which is
an aggregate of pixels, and it is so arranged that a position of
each pixel on an image element can be specified. For instance, the
position of each pixel is specified by a coordinate system with an
optical axis of each camera as an origin point.
First, a description will be given on a measurement operation by
the surveying instrument 1 by referring to FIG. 6A, FIG. 6B and
FIG. 6C. To simplify the explanation, in FIG. 6A, the optical
prisms 41a and 41b are shown by separating the prism elements 42a
and 42b and the prism elements 43a and 43b. Further, the prism
elements 42a and 42b and the prism elements 43a and 43b as shown in
FIG. 6A are in a state in which maximum deflection angles can be
obtained. Further, the minimum deflection angle is a position where
either one of the optical prisms 41a or 41b is rotated by
180.degree., the deflection angle becomes 0.degree., and an optical
axis of a laser beam as projected (the distance measuring optical
axis 4) becomes parallel to the projection optical axis 31.
A distance measuring light is emitted from the light emitting
element 32, and the distance measuring light is turned to a
parallel luminous flux by the projecting lens 33 and projected
toward an object to be measured or a measurement target area
through the distance measuring light deflecting unit 36a (the prism
elements 42a and 42b). Here, by passing through the distance
measuring light deflecting unit 36a, the distance measuring light
is deflected to a direction as required and projected by the prism
elements 42a and 42b.
The reflected distance measuring light as reflected by the object
to be measured or by the measurement target area is incident
through the reflected distance measuring light deflecting unit 36b
(the prism elements 43a and 43b) and is focused on the
photodetector 38 by the image forming lens 39.
Since the reflected distance measuring light passes through the
reflected distance measuring light deflecting unit 36b, the optical
axis of the reflected distance measuring light is deflected by the
prism elements 43a and 43b so as to coincide with the light
receiving optical axis 37 (FIG. 6A).
By a combination of the rotation positions of the optical prism 41a
and the optical prism 41b, the deflecting direction and deflection
angle of the distance measuring light to be projected can be
arbitrarily changed.
Further, under a condition where a positional relation between the
optical prism 41a and the optical prism 41b is fixed (under a
condition where the deflection angles obtained by the optical prism
41a and the optical prism 41b are fixed), by rotating the optical
prism 41a and the optical prism 41b integrally by the motors 47a
and 47b, a locus drawn by the distance measuring light passing
through the distance measuring light deflecting unit 36a becomes a
circle with the distance measuring optical axis 4 as the
center.
Therefore, by rotating the optical axis deflecting unit 36 while
emitting the laser beam from the light emitting element 32, the
distance measuring light can be scanned by the locus of the
circle.
It is to be noted that it is needless to say that the reflected
distance measuring light deflecting unit 36b is rotated integrally
with the distance measuring light deflecting unit 36a.
Next, FIG. 6B illustrates a case in which the optical prism 41a and
the optical prism 41b are relatively rotated. Assuming that a
deflecting direction of the optical axis as deflected by the
optical prism 41a is a deflection "A" and the deflecting direction
of the optical axis as deflected by the optical prism 41b is a
deflection "B", the deflection of the optical axis by the optical
prisms 41a and 41b becomes a synthetic deflection "C" as an angle
difference .theta. between the optical prisms 41a and 41b.
Therefore, each time the angle difference .theta. is changed, by
rotating the optical axis deflecting unit 36 once, the distance
measuring light can be scanned linearly.
Further, as illustrated in FIG. 6C, when the optical prism 41b is
rotated at a rotating speed lower than the rotating speed of the
optical prism 41a, since the distance measuring light is rotated
while the angle difference .theta. is gradually increased, the
scanning locus of the distance measuring light becomes a spiral
form.
Furthermore, by individually controlling the rotating direction and
the rotating speed of the optical prism 41a and the optical prism
41b, the scanning locus of the distance measuring light is made in
an irradiating direction (scanning in the radial direction) with
the projection optical axis 31 as the center or in a horizontal
direction or in a vertical direction or the like, and various
scanning states can be obtained.
As a mode of measurement, by performing a distance measurement by
fixing the optical axis deflecting unit 36 (the optical prisms 41a
and 41b) per each deflection angle as required, the distance
measurement can be performed with respect to a specific measuring
point. Further, by executing the distance measurement while
changing the deflection angles of the optical axis deflecting unit
36, that is, by executing the distance measurement while scanning
the distance measuring light, distance measurement data with
respect to a measuring point on the scanning locus can be
acquired.
Further, the projection directional angle of each distance
measuring light can be detected by the rotation angles of the
motors 47a and 47b, and by associating the projection directional
angle with the distance measurement data, three-dimensional
distance measurement data can be acquired.
Further, a tilting of the projection optical axis 31 with respect
to the horizontal can be detected by the attitude detecting unit
26, and based on the tilting as detected by the attitude detecting
unit 26, the distance measurement data is corrected and the
distance measurement data with high accuracy can be acquired.
Next, in the present embodiment, the three-dimensional distance
measurement data is acquired and image data can also be
acquired.
When the object to be measured is selected, the surveying
instrument 1 is directed toward the object to be measured so that
the object to be measured is captured by the image pickup unit 27.
An image acquired by the image pickup unit 27 is displayed on the
display unit 11.
Since the image acquired by the image pickup unit 27 is equal to or
approximately equal to a measurement area of the surveying
instrument 1, and the measuring operator can visually specify the
measurement area easily.
Further, since the distance measuring optical axis 4 and the image
pickup optical axis 5 are parallel to each other, and both the
optical axes are in a known relation, the arithmetic processing
unit 24 can match the image center with the distance measuring
optical axis 4 on the image by the image pickup unit 27. Further,
by detecting the projection directional angle of the distance
measuring light, the arithmetic processing unit 24 can specify a
measuring point on the image based on the projection directional
angle. Therefore, it is possible to easily associate the
three-dimensional data of the measuring point with the image, and
the image as acquired by the image pickup unit 27 can be turned to
an image with the three-dimensional data.
FIG. 7A and FIG. 7B show a relation between an image acquired by
the image pickup unit 27 and a locus obtained on the measuring
point. It is to be noted that FIG. 7A shows a case in which the
distance measuring light is scanned in a concentric and
multi-circular form and FIG. 7B shows a case in which the distance
measuring light is reciprocally scanned linearly. In the figure,
reference numeral 17 denotes a scanning locus and the measuring
points are positioned on the scanning locus 17.
In the description as given above, the distance measuring light
deflecting unit 36a and the reflected distance measuring light
deflecting unit 36b are formed on the same optical prism and
integrated together. On the other hand, the projection optical axis
31 and the light receiving optical axis 37 are separated from each
other, the distance measuring light deflecting unit 36a and the
reflected distance measuring light deflecting unit 36b are provided
individually on the projection optical axis 31 and the light
receiving optical axis 37, and further it may be so arranged that
the distance measuring light deflecting unit 36a and the reflected
distance measuring light deflecting unit 36b are synchronously
rotated so that the deflecting directions by the distance measuring
light deflecting unit 36a and the reflected distance measuring
deflecting unit 36b coincide with each other.
A description will be given below on a measuring operation of the
surveying instrument 1.
First, referring to FIG. 8, FIG. 9A, FIG. 9B and FIG. 9C, a
description will be given on a case where the verticality of the
object to be measured is determined.
It is to be noted that in a description as given below, as shown in
FIG. 8, an inclining of the object to be measured 81 means a
tilting with respect to a vertical line 83.
FIG. 9A shows an image 82 of the object to be measured 81 as picked
up by the image pickup unit 27. Since the image 82 includes the
tilting of the image pickup unit 27, the verticality as obtained
from the image 82 itself is different from an actual
verticality.
When the image 82 is picked up, a tilt angle and a tilting
direction of the image pickup unit 27, i.e. a tilt angle and a
tilting direction of the surveying instrument 1 with respect to the
horizontal, can be detected by the attitude detecting unit 26. The
tilt angle and the tilting direction as detected are a tilting and
a tilting direction of the image at the time of an image pickup.
The arithmetic processing unit 24 calculates a tilting of the image
with respect to the horizontal or vertical based on this tilting
and tilting direction, and shows a plurality of vertical lines 83
and a plurality of horizontal lines 84 in the image based on this
calculation result (FIG. 9B).
Since the image 82 is a perspective image (an image in which a near
object is displayed large and a far object is displayed small), a
distance between the vertical lines 83 becomes narrower toward the
upper part in the image 82. The arithmetic processing unit 24
performs an image processing so that the vertical lines 83 become
in parallel to each other. Hereinafter, the image after the image
processing is referred as a vertical image 82' (FIG. 9C).
In the vertical image 82', if a point on the object to be measured
81 which should be vertical, a ridge line of a pillar or a wall,
for instance, is compared with the vertical lines 83, a vertical
condition of the object to be measured 81 can be visually judged
from the image.
Further, because the distance measuring light can be irradiated to
an arbitrary point in the image by the optical axis deflecting unit
36, a measurement may be performed on at least two points of the
object to be measured 81, preferably on a specific point, e.g. on
two upper and lower points of the pillar, or the measurement may be
performed on two points on the vertical line 83, and then
three-dimensional coordinates of the two points may be acquired,
and an accurater vertical condition may be determined based on
coordinate values.
Next, referring to FIG. 10, a description will be given on a first
embodiment to perform a trilateration by using the surveying
instrument 1.
The surveying instrument 1 is installed in such a manner that a
lower end of the monopod 2 is positioned at a first installation
reference point R1 (a first position), which is a known point (the
coordinates are already known).
A first image is obtained with respect to the object to be measured
by the image pickup unit 27, and a measuring point 87 is selected
from the image. Here, a selection of the measuring point 87 may be
confirmed visually in the image or may be selected by an image
processing such as a feature extraction (an edge extraction), or
the like.
The distance measuring optical axis 4 is directed toward the
measuring point 87, and a slope distance to the measuring point 87
is determined. It is to be noted that the distance measuring
optical axis 4 and the image pickup optical axis 5 are regarded to
be in a parallel condition.
A tilt angle of the distance measuring optical axis 4 with respect
to the horizontal at this moment is detected by the attitude
detecting unit 26. Therefore, a horizontal distance to the
measuring point 87 is obtained by the arithmetic processing unit 24
based on this tilt angle and the slope distance.
Further, a tilt angle of the monopod 2 with respect to the vertical
is also detected by the attitude detecting unit 26. Since the
length of the monopod 2 is already known, displacement D1 of the
surveying instrument 1 in a horizontal direction with respect to
the first installation reference point R1 is obtained by the
arithmetic processing unit 24 based on the tilt angle.
Further, the surveying instrument 1 is installed in such a manner
that the lower end of the monopod 2 is positioned at a second
installation reference point R2 (a second position), which is a
known point (the coordinates are already known).
A second image is obtained with respect to the object to be
measured by the image pickup unit 27, and a measuring point 87'
which is common to the measuring point 87 is specified on the
image. The distance measuring optical axis 4 is directed toward the
measuring point 87' from the second installation reference point
R2, and a slope distance to the measuring point 87' is
determined.
It is to be noted that an operation for specifying the measuring
point 87' in the second image may be performed by an image matching
as described later.
The tilt angle of the distance measuring optical axis 4 with
respect to the horizontal at the second installation reference
point R2 is detected by the attitude detecting unit 26. Therefore,
a horizontal distance to the measuring point 87' is obtained by the
arithmetic processing unit 24 based on this tilt angle and the
slope distance.
Further, the tilt angle of the monopod 2 with respect to the
vertical at the second installation reference point R2 is also
detected by the attitude detecting unit 26. Displacement D2 of the
surveying instrument 1 in the horizontal direction with respect to
the second installation reference point R2 is obtained by the
arithmetic processing unit 24 based on the length of the monopod 2
and the tilt angle.
Based on the horizontal displacements D1 and D2 and a distance
between the first installation reference point R1 and the second
installation reference point R2, a distance between the surveying
instrument 1 at the first installation reference point R1 and the
surveying instrument 1 at the second installation reference point
R2 (a base line length B (see FIG. 10)) is obtained by the
arithmetic processing unit 24.
Thus, based on the horizontal distance from the first installation
reference point R1, the horizontal distance from the second
installation reference point R2, and the base line length B, the
trilateration is performed with respect to the measuring point
87.
Further, referring to FIG. 11, a description will be given on a
second embodiment of the trilateration.
As shown in FIG. 11, a surveying instrument 1 is installed in such
a manner that a lower end of a monopod 2 is positioned at the
installation reference point R, which is a known point (the
coordinates are already known).
The surveying instrument 1 is tilted approximately in parallel and
in one direction with respect to an object to be measured 81, a
tilted state is regarded as a first position 86, and an image 85
(not shown) of the object to be measured 81 is acquired at the
first position 86. The image 85 is displayed on a display unit 11.
While observing the image 85, directions of a distance measuring
optical axis 4 and an image pickup optical axis 5 are set so that a
measuring position and a measuring area as planned are included in
the image 85. After setting, one or more measuring points 87 are
selected in the image 85. It is to be noted that the measuring
point 87 is a point which is extracted from the image 85 by an
image processing such as a feature extraction (an edge extraction),
or the like.
Further, under a condition where the surveying instrument 1 is
tilted, an optical axis deflecting unit 36 is operated. A position
of the measuring point 87 in the image 85 can be obtained from a
deviation from the image pickup optical axis 5 on an image pickup
element 49. Further, a field angle with respect to the image pickup
optical axis 5 is obtained based on the position on an image pick
up element 49. Therefore, a deflection angle of the measuring point
87 with respect to the image pickup optical axis 5 can be
obtained.
The arithmetic processing unit 24 controls the optical axis
deflecting unit 36 and deflects the distance measuring optical axis
4 to the deflection angle as obtained.
The distance measuring optical axis 4 is directed toward the
measuring point 87, and a distance measurement is performed with
respect to the measuring point 87 from the first position 86 (a
slope distance is obtained).
The tilt angle of the surveying instrument 1 with respect to the
horizontal is detected by the attitude detecting unit 26.
Therefore, a tilt angle of the image pickup optical axis 5 with
respect to the horizontal is obtained based on a detection result
of the attitude detecting unit 26 and on a deflection angle by the
optical axis deflecting unit 36. The horizontal distance to the
measuring point 87 is determined by the arithmetic processing unit
24 based on the tilt angle of the image pick up optical axis 5 and
on the slope distance.
Since a distance L between the lower end of the monopod 2 (i.e. the
installation reference point R) and a mechanical reference point O
of the surveying instrument 1 is already known, based on the
distance L and a tilt angle of an axis 3 (see FIG. 1) at the first
position 86, a three-dimensional position (three-dimensional
coordinates) of the mechanical reference point O with respect to
the installation reference point R can be calculated.
Next, the surveying instrument 1 is tilted approximately in
parallel and in the other direction with respect to the object to
be measured 81, and an image 85' (not shown) of the object to be
measured 81 at a second position 86' under a tilted state is
acquired. Further, a direction of the distance measuring optical
axis 4 is adjusted so that the image 85' is within the same area or
approximately same area as the image 85.
The image matching is carried out with respect to the image 85 and
the image 85', and the measuring point 87 as selected in the image
85 is specified in the image 85'. The measuring point 87 is
superimposed on the image 85' and is displayed on the display unit
11.
The optical axis deflecting unit 36 is operated, the distance
measuring optical axis 4 is directed toward the measuring point 87
as specified, and the distance measurement (a measurement of the
slope distance) is performed with respect to the measuring point 87
from the second position 86'. A tilt angle of the surveying
instrument 1 at the second position 86' is detected by the attitude
detecting unit 26. The horizontal distance from the second position
86' to the measuring point 87 is obtained by the arithmetic
processing unit 24 based on the tilt angle of the surveying
instrument 1, the deflection angle as obtained by the optical axis
deflecting unit 36 and the slope distance.
Based on the distance L and on the tilt angle of the axis 3 (see
FIG. 1) at the second position 86', the three-dimensional position
(the three-dimensional coordinates) of the mechanical reference
point O at the second position 86' with respect to the installation
reference point R can be calculated.
Based on the three-dimensional position (the three-dimensional
coordinates) of the mechanical reference point O at the first
position 86 and on the three-dimensional position (the
three-dimensional coordinates) of the mechanical reference point O
at the second position 86', distances between the mechanical points
O (the base line length B) can be obtained.
Therefore, distances between the measuring positions and horizontal
distances of two sides from each of the measuring positions to the
measuring point can be determined respectively, and
three-dimensional coordinates of the measuring point 87 with the
installation reference point R as a reference can be
determined.
Further, by associating the image as matched and results of a
three-dimensional measurement, an image with three-dimensional data
can be acquired.
As described above, an angle measurement is not included in a
measuring operation. For this reason, the angle measurement, which
requires high accuracy and with high operational burden, is omitted
and an efficiency of the measuring operation can be improved.
It is to be noted that a specification of the measuring point in
the image by the image matching as described above are disclosed in
Japanese Patent Laid-Open Publication No. 2009-210388.
Next, a description will be given on the image matching in the
present embodiment.
First, a description will be given on a general image matching by
referring to FIG. 12.
In order to perform a three-dimensional measurement on images
acquired at two points, a relative orientation operation is
required.
In a case where the images are acquired at the two points,
directions of a camera are determined by .phi., .omega. and
.kappa..
Therefore, directions of the camera at the two points are expressed
by .phi.1, .omega.1, .kappa.1, .phi.2, .omega.2 and .kappa.2,
respectively.
In the general relative orientation, .phi.1, .omega.1, .kappa.1,
.phi.2, .omega.2 and .kappa.2 are unknown. This means that .phi.1,
.omega.1, .kappa.1, .phi.2, .omega.2 and .kappa.2 are obtained
based on common points in the two images. In this case, required
common points are 6 or more.
As shown in FIG. 12, a projection center O1 on the left side is
regarded as an origin point of a model coordinate system, and a
line connecting the projection center O1 with a projection center
O2 on the right side is regarded as an X-axis. As for a scale, a
base line length is regarded as a unit length. Here, if the
coordinate system as shown in FIG. 12 is corresponded to FIG. 1,
the distance measuring optical axis 4 corresponds to a Z-axis, and
the horizontal reference line 6 corresponds to the X-axis.
Parameters as obtained in this case are: a rotation angle .kappa.1
of the Z-axis of the camera on the left side, a rotation angle
.phi.1 of a Y-axis of the camera on the left side, a rotation angle
.omega.1 of the X-axis of the camera on the left side, a rotation
angle .kappa.2 of the Z-axis of the camera on the right side, a
rotation angle .phi.2 of the Y-axis of the camera on the right
side, and a rotation angle .omega.2 of the X-axis of the camera on
the right side. In this case, since the rotation angle .omega.1 of
the X-axis of the camera on the left side is 0, there is no need to
consider.
Therefore, .phi.1, .kappa.1, .phi.2, .omega.2 and .kappa.2 are
unknown quantities.
Further, with respect to .phi.1, .kappa.1, .phi.2, .omega.2 and
.kappa.2, each parameter is determined by solving an equation (1)
as shown in FIG. 13.
In the equation (1):
.kappa.1: The rotation angle of the Z-axis of the left side
camera
.phi.1: The rotation angle of the Y-axis of the left side
camera
.kappa.2: The rotation angle of the Z-axis of the right side
camera
.phi.2: The rotation angle of the Y-axis of the right side
camera
.omega.2: The rotation angle of the X-axis of the right side
camera
In the present embodiment, tilt angles in two directions with
respect to the horizontal of the surveying instrument 1 (i.e. the
image pickup unit 27) are detected by the attitude detecting unit
26 (see FIG. 1). That is, .kappa.1, .kappa.2 and .omega.2 at the
two points become known, respectively. Therefore, unknown
quantities are limited only to .phi.1 and .phi.2, and a calculation
can be extensively simplified.
When a trilateration is performed, each of inner angles can be
calculated by using the theorem of cosines, and .phi.1 and .phi.2,
which are inner angles at the first position 86 and the second
position 86', can be easily obtained. Thus, the calculation of a
relative orientation can be simplified.
Further, in the present embodiment, the perspective image can be
turned to the vertical image by the image processing. By using the
vertical image for the image matching, the relative orientation
operation is not required, and the image matching can be simplified
further. Further, by adopting the vertical image, an epipolar line
can be formed immediately, and the vertical image becomes a
three-dimensional model by a parallax measurement. Thus, a
processing time can be extremely shortened.
Further, a description will be given on a third embodiment of the
trilateration by referring to FIG. 14.
A surveying instrument 1 is installed at a first installation
position (a known installation reference point R) 88 via a monopod
2. A mechanical reference point O at this time is regarded as a
first position 86. From the first position 86, a first image is
acquired with respect to an object to be measured, and a measuring
point 87 is selected in the image. A distance measurement is
performed by a distance measuring unit 23 with respect to the
measuring point 87 as selected, and a tilting of the surveying
instrument 1 at the time of the distance measurement is detected by
the attitude detecting unit 26. Based on this tilt angle and a
distance L of the monopod 2, a positional relation between the
installation reference point R and the first position 86 is
determined. Further, the first position 86 is calculated by the
arithmetic processing unit 24.
The surveying instrument 1 is installed at a second installation
position 88', which is separated by a distance as required from the
installation reference point R. The mechanical reference point O at
this time is regarded as a second position 86'. The distance
measuring optical axis 4 is directed toward the installation
reference point R from the second position 86', and the distance
measuring unit 23 measures a distance between the second position
86' and the installation reference point R (a slope distance). A
tilt angle of the surveying instrument 1 at the time of a slope
distance measurement is detected by the attitude detecting unit
26.
Based on this tilt angle and the distance L of the monopod 2, a
positional deviation "f" of the second position 86' with respect to
the second installation position 88' is measured. Further, a
horizontal distance H between the second position 86' and the
installation reference point R (the first installation position 88)
is obtained by the arithmetic processing unit 24 based on this tilt
angle and a result of the slope distance measurement. This
horizontal distance H is corrected (added) by the positional
deviation "f", and the base line length B (a distance between the
first installation position 88 and the second installation position
88') is calculated.
From the second position 86', the distance measuring optical axis 4
is directed toward the measuring point 87, and a second image of an
area including the measuring point 87 is acquired. By a matching of
the first image and the second image, the measuring point 87 is
specified in the second image, and the distance measuring unit 23
performs the distance measurement with respect to the measuring
point 87. A tilt angle at the time of the distance measurement is
detected by the attitude detecting unit 26 (in a case where the
tilt angle is different from the tilt angle when the slope distance
is obtained).
Based on the tilt angle and on the distance L at the time of the
distance measurement of the measuring point 87 at the first
position 86, a deviation of the first position 86 with respect to
the first installation position 88 is obtained, and based on the
tilt angle and the distance L at the time of the distance
measurement of the measuring point 87 at the second point 86', a
deviation of the second position 86' with respect to the second
installation position 88' is obtained. By the arithmetic processing
unit 24, the position of the first position 86 with respect to the
first installation position 88 is calculated, and the position of
the second position 86' with respect to the second installation
position 88' is calculated respectively.
Thus, a true base line length B' between the first position 86 and
the second position 86' at the time of the measurement of the
measuring point 87 is calculated.
Based on the true base line length B', on the results of the
distance measurement of the measuring point 87 from the first
position 86, and on the results of the distance measurement of the
measuring point 87 from the second position 86', the trilateration
with respect to the object to be measured is performed.
In the present third embodiment, since the true base line length B'
can be taken longer, a measurement can be performed with respect to
the object to be measured which is positioned at a long distance
with high accuracy.
Furthermore, referring to FIG. 15, a description will be given on a
fourth embodiment of the trilateration.
In the present fourth embodiment, a GNSS (Global Navigation
Satellite System) device 89 is provided on a surveying instrument
1.
By the GNSS device 89, three-dimensional coordinates (GNSS
coordinates) of the surveying instrument 1 at a first position can
be acquired, and further three-dimensional coordinates of the
surveying instrument 1 at a second position can be acquired.
Therefore, a positional information of the surveying instrument 1
required in order to measure a measuring point 87 can be acquired,
and further a base line length B can be also calculated based on
the three-dimensional coordinates of the surveying instrument 1 at
the first point and the second point. Therefore, the trilateration
can be performed.
In the embodiments as given above, a description has been given on
a case where the surveying instrument 1 is provided on an upper end
of a monopod 2 with a known length. In these embodiments, the
monopod 2 is installed in such a manner that a lower end is
positioned at a known point, and a tilt angle of the monopod 2 is
detected by an attitude detecting unit 26 as built in the surveying
instrument 1.
Based on the known length of the monopod 2 and on the tilt angle
and tilting direction as detected by the attitude detecting unit
26, the arithmetic processing unit 24 can calculate a position of a
mechanical reference point O of the surveying instrument 1 with
respect to the known point, that is, a coordinate position of the
mechanical reference point O. Therefore, the monopod 2 and the
attitude detecting unit 26 functions as a coordinates acquiring
unit for obtaining the coordinate position of the mechanical
reference point O of the surveying instrument 1.
Therefore, the GNSS device 89 may be used as a coordinates
acquiring unit for obtaining the coordinate position of the
mechanical reference point O. In a case where the GNSS device 89 is
used as a coordinates acquiring unit 90, the monopod 2 may be
omitted (see FIG. 15). Further, in the GNSS device 89, it is
possible to acquire coordinates with a global coordinate as a
standard, and a versatility of a measurement result is
increased.
* * * * *